Porsche Forum Australia

915 (‘85) swap into 1972 911T

Add to repair workspace

New repair projectOpen repair workspace

Original source

2 captured repliesPartial discussion capture · Source accounts, not a confirmed diagnosis

THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCH915 (‘85) swap into 1972 911T

Leading reported evidence

Install with a 2

Performed · outcome unconfirmed

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that performed work without a confirmed outcome: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed · Original poster
I have a viper green 1972 911T, fitted with a 2.7L and magnesium case 915 from a ‘74 911.
Original post Read captured discussion
915 (‘85) swap into 1972 911T

Read full discussion summary

Leading evidence: 'Install with a 2' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Install with a 2' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.

Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.

Read captured replies

1 matching discussions · 2 captured posts examined · 1 partial discussions

Compare 1 other evidence results

Install with course spline 4 hole flanges

Performed · outcome unconfirmed

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that performed work without a confirmed outcome: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed · Original poster
The control arms are original steel control arms for the ‘72 and the trans is fitted with course spline 4 hole flanges.
Original post Read captured discussion
915 (‘85) swap into 1972 911T

Frequently discussed actions (2)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

Install with a 2

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that performed work without a confirmed outcome: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed · Original poster
I have a viper green 1972 911T, fitted with a 2.7L and magnesium case 915 from a ‘74 911.
Original post Read captured discussion
915 (‘85) swap into 1972 911T

Install with course spline 4 hole flanges

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that performed work without a confirmed outcome: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed · Original poster
The control arms are original steel control arms for the ‘72 and the trans is fitted with course spline 4 hole flanges.
Original post Read captured discussion
915 (‘85) swap into 1972 911T

Coverage and how to read this overview

Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.

2 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.

Porsche Forum Australia: 1 discussions

0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.

0 acknowledgements have no verified action link; they do not establish a repair result.

Generation: 20261026T152433Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

Hi PFAers I am looking to do a transmission swap on my 1972 911T. I would be grateful for any advice you can share for a problem I have. I have a viper green 1972 911T, fitted with a 2.7L and magnesium case 915 from a ‘74 911. The control arms are original steel control arms for the ‘72 and the trans is fitted with course spline 4 hole flanges. I recently bought a rebuilt 3.2L and alloy case 915 from an ‘85 911. The trans has fine spline 6 hole flanges. The problem: the fine spline 6 hole flanges (from the ‘85) are thinner and have a smaller bolt pattern than the course spline 4 hole flanges (from the ‘74). This means the axles, CVs, and control arms can’t bolt straight up. The question: what is the easiest way to get the alloy case ‘85 915 in the car? Do I need SC/Carerra control arms and axles? Or does someone make CV flanges that would bolt into the newer 915 to be able to use the original CV shafts (eg a fine spline, 4 hole flange that has the larger bolt pattern)? I am hoping this is no reinventing the wheel as I’ve seen plenty of long hoods cruising around with SC/Carerra drive lines. Thanks in advance for any advice you can share. Cheers Jono

POST 2Original post

I am no expert, but can offer the following: I recently had my late year 915 rebuilt with a new lsd etc. and part of the build was to convert to a fine spline turbo flange. This required new axles to be mated with the flange shafts. My guesstimate is that you may be able to purchase the appropriate axles to work, (which I may incidentally have as spare parts) Bob Wynn did the work for me, might be worth giving them a call to ask what the way forward is.

This is a source reference. Confirm exact model applicability in the original material.